SPRINGFIELD - After 15 days of testimony from dozens of witnesses, a jury in Hampden Superior Court took just three hours to return its guilty verdict in the first-degree murder trial of Eric B. Denson for the 2010 fatal stabbing of Cathedral High School soccer star Conor W. Reynolds.

And, as swiftly as the jurors convicted Denson on Tuesday, the judge in the case, Peter A. Velis, imposed the mandatory life sentence to state prison after a tear-choked hearing during which members of Reynolds’ family shared the impact the teen’s killing has had on their lives.

Hampden District Attorney Mark G. Mastroianni, for whom the case marked his first murder trial since taking office in January, called the verdict a just one which was supported by the prosecution’s evidence.

“It’s a just verdict,” Mastroianni said. “It’s a difficult day for the Reynolds family, it’s a difficult day for the Denson family as well. Two young lives are lost, but Conor will never be back. Conor is gone forever so it’s a difficult day. There are really no winners here, but we’re very happy and very pleased with the verdict.”

The 17-year-old Reynolds was stabbed in the neck during a birthday party at a packed nightclub on St. James Avenue on March 13, 2010. The former Blue Fusion Bar & Grill was described during trial testimony as a chaotic scene where several hundred young people had flocked for the private party.

Testimony was that the stabbing came amidst a scuffle which broke out involving several Cathedral students. When Reynolds walked over to see what was happening, he was confronted by a black male wearing a red hat and black jacket, his girlfriend and other witnesses testified.

The defense had argued that the murder charge was concocted from false assumptions, unreliable testimony and weak physical evidence gathered by investigators who never considered any other suspects.

The prosecution countered that DNA evidence, surveillance video from a nearby convenience store and eyewitness testimony presented during the trial provided overwhelming proof that it was Denson who had killed Reynolds.

Although the trial extended over the course of three weeks, the case presented by the prosecution involved a “fact pattern (that was) very succinct,” Mastroianni said. “The fact pattern is short, it’s abbreviated and it’s to the point when you get down to two or three witnesses and the descriptions that matter. And, the jury obviously heard that.”

Defense lawyers Harry Miles, David Rountree and Bonnie Allen declined to comment about the verdict.

Denson was also convicted of a charge of assault and battery with a dangerous weapon. Peter D’Amario, a classmate and friend of Reynolds, testified he was cut by the knife as the assailant stabbed his friend.

Velis ordered Denson serve a 1½-year state prison sentence on that charge, to be followed by the life sentence.

In asking for the consecutive sentences, Mastroianni said the way Reynolds had died was “truly horrible, as was everything about this case.”

Commenting during the sentencing, the judge said he had “observed these kinds of situations for years” but had never seen two families more torn apart then Reynolds’ and Denson’s. Large contingents of members of both families attended the trial over the course of the three weeks.

“The loss of this courageous young man,” the judge said, “has left its mark.”

Recalling the night her son died, Reynolds’ mother, Kate Reynolds, said her family “cried ourselves to sleep that night. That Sunday morning and every day after, we wake up, wish it was all a dream then remember that it’s a reality. It is amazing how many lives our son has touched in his short 17 years of life.”

The judge also heard statements from Reynolds’ father, his younger brother, Ryan Reynolds, an aunt and his grandparents.

Sara Warren Gardner, Kate Reynolds’ sister and Conor’s aunt, told Velis, “In that split second when he (Denson) chose to strike out and take Conor’s life, he rocked the world of hundreds of people - Conor’s mother and father, his brothers, as well as his many friends.”